Optoelectronic components, for example light-emitting diodes (LEDs, Light-Emitting Devices), are used in various technical applications. In particular, LEDs are being used increasingly for lighting purposes. Depending on the respective application, different LEDs having defined light characteristics may be produced. As a result of production, however, more or less pronounced variations in the light characteristics occur in LEDs of the same component range. While a certain variance of the light properties is unproblematic for some fields of use of LEDs, maximally accurate knowledge of the light characteristics of the LEDs used is a prerequisite for particular special applications. Thus, the LED light perceived by the human eye is in general already characterized sufficiently by means of few macroscopic data, for example photometric brightness and color locus. For applications which record LED light in particular by a sensor, it is advantageous to have maximally accurate knowledge of the characteristics of individual LEDs. For LED light which is recorded by a sensor, besides the macroscopic data such as radiometric brightness, in particular the light power spectrum, which has a much larger data volume, is thus of interest. An example which may be mentioned here is a cell phone, the camera module of which records the light of an internal LED flash.
For LED components having a plurality of individually controllable colors (LED chips), there is a correspondingly enlarged data volume. Storage of these data in the memory modules integrated in the LED component therefore requires a relatively large memory volume, which inter alia is associated with relatively high production costs. Since the size of the corresponding memory modules also increases with the storage capacity, large memory volumes are relatively critical precisely in application fields having a significantly restricted installation space.
The methods to date for the characterization of LED components comprise, inter alia, so-called binning. In this case, the LED components are divided into so-called bins, each bin being assigned a parameter range. In the case of a relatively fine distribution, some parameters, for example brightness and color, can be characterized correspondingly accurately for each LED component by means of binning. Spectral information, however, cannot be handled meaningfully by binning because of the amount of data.
For the characterization of individual LED components, it is furthermore possible to use so-called data files, the LEDs being for example already measured at the chip level (wafer maps) and provided with unique codes (for example laser codes). The data must in this case be communicated to the user offline, for example in the form of data files which allow assignment of the data with the aid of the unique code of the LED components.
If the power spectra are stored in the memory modules of the LED components, the need arises to use correspondingly large and therefore expensive memory modules. Otherwise, only few data for characterization of the LED component can be stored.